The present invention relates generally to a device for retaining the corners of a bed sheet, blanket or the like in position tucked under respective corners of a mattress so as to not be dislodged therefrom during normal use.
Ever since man first placed a cover over a mattress he has been plagued by the problem of keeping that cover in position on the mattress. Attempts to obviate this problem have included forming as by sewing a pocket in corners of the cover configured to closely fit about a corresponding mattress corner with this attempted solution currently commercially available in the form of so called "fitted sheets". Such fitted sheets represent a reasonable solution to the problem when employed on conventional mattresses of the type containing coil springs, foam rubber or other padding materials where the mattress has a relatively strong tendency to maintain its shape despite pulling and tugging on the cover, however, with the advent of waterbeds where a large plastic water tight enclosure is positioned within a rigid frame and filled with water, such fitted sheets have not proven to be an entirely satisfactory solution to the problem. It would be highly desirable to provide a bed cover anchoring arrangement which could be employed with either fitted sheets or more conventional unfitted bed clothes and which would be applicable either to mattresses of conventional design or to waterbed mattress.
Less commercially well known attempts to solve this ever present problem are illustrated for example in U.S. Pat. No. 731,844 and U.S. Pat. No. 4,276,667 issued over three quarters of a century apart and illustrating the persistence of the problem. In the earlier patent, a hook arrangement grasps the bed cover at one end and a second hook arrangement grasps springs beneath the mattress at the other end effectively tying the bed cover and springs together. Clearly, accessible springs are required for this technique. In the more recent patent, a base having tiny slippage preventing hooks is lodged between upper and lower mattress sections and a rubber block is held against a mattress side wall portion with the retained bed cover being gripped therebetween. With this latter approach, slippage of the bed cover between the rubber block and mattress edge are still possible and the structure does not fit flush with the edge of the mattress. Thus, neither of these patented approaches are suitable for a waterbed environment.